Within recent years, there has been a wide and increasing acceptance of the use of radioisotopes for the diagnosis and treatment of various body malfunctions. As a result of the radioactivity of the radioisotope, considerable hazard is involved to the personnel responsible for injecting the radioisotope within a patient's body. While the dosages applied are themselves not lethal to the patient, constant and repeated contacts with the serums over an extended period of time can create very harmful effects on the medical operators who administer them.
A more recent diagnostic procedure requiring the use of radioisotopes is the clinical use of positron emission tomography (PET). PET has been used for approximately 15 years; and is a non-invasive imaging technique that is used to measure the uptake and distribution of short lived positron emitting radiopharmaceuticals or radiotracers. These radiotracers are generally produced on-site at the hospital in a cyclotron and then injected into the patients prior to imaging. Positron emitting radiotracers are of interest because of their use in transaxial tomography.
Although a variety of positron emitting radiotracers are employed in the study of epilepsy, dementia and cerebral blood flow to mention a few, a widely used radiotracer is fluorodeozyglucose (FDG). FDG is transported from the blood to the brain substance in a manner similar to glucose. FDG is phosphorylated and trapped in the brain substance where there is limited metabolism that allows adequate time for tomographic positron imaging. PET using FDG permits a non-invasive method of quantifying cerebral metabolism in humans and thereby provides a physiological tool that discerns pathologic conditions before morphologic manifestations are discernable. Thereby, the clinical use of PET has increased considerably during the past few years.
Recent studies have indicated that PET exposes the technologist to the largest doses of radiation compared to other modalities. Protection from radiation exposure is achieved primarily by three factors: time, distance, and shielding. Radiation exposure is directly proportional to the amount of time spent in a radiation field. The quicker the operator can remove himself from the radiation field, the less radiation exposure he will experience. Distance provides a second form of protection in that the dose to an individual decreases with the square of the distance from the radiation field. Therefore, if one doubles the distance between an individual and a source of radiation, the radiation exposure to the individual is reduced to one-fourth. Shielding provides the third form of protection. Shielding is of two general types: bench top and syringe shielding. Bench top shields are generally constructed of lead bricks and usually have a viewing and access porthole so that the operator can remove the syringe from its lead casing to be placed within another bench top shield on a transport apparatus. The operator uses the transport apparatus to move the syringe to the patient testing site. Many times the transport apparatus itself is not sealed in all directions allowing more exposure to the operator.
The current invention addresses these forms of protection from radiation exposure by limiting the time that the operator is exposed in the radiation field, by providing a remote injection device and thereby adding distance during the injection procedure, and finally by providing an adequate shielding device during the transport and administration of the radioactive material.